Mapping of physiological structures and various physiological parameters sensed within the body is an important technological component of the practice of medicine. Such mapping procedures can be time-consuming, and often the imaging modality utilized to capture geometric data for the mapping process requires patient exposure to X-rays. The time during which a patient undergoes a mapping procedure and the accompanying interventional treatment and the patient's total exposure to X-ray radiation are both important risk factors for medical mapping procedures; both time and X-ray exposure are desirably minimized.
The inventive method disclosed herein is directed toward generating such maps much more rapidly, and although the inventive method may be applicable to the mapping of physiological parameters other than parameters associated with the heart, much of the disclosure herein is made within the area of cardiology. Electrocardiology is an area of cardiology in which this invention is particularly and advantageously applicable.
U.S. patent application Ser. No. 13/607,163 (Sra et al.), titled “Automatically Determining 3D Catheter Location and Orientation Using 2D Fluoroscopy Only” and published as Published Application No. 2013/0243153, discloses a novel system for extracting the third dimension from a stream of single-plane fluoroscopic images. The system uses only 2D image information to determine the 3D location and orientation of a catheter during medical procedures. For convenience, such system may be called the Catheter Tip 3D Location System and may be referred to herein as C3DLS to shorten the terminology. The Sra et al. application is hereby incorporated herein for reference in its entirety. The initialization and calibration process within C3DLS incorporates the use of two single-plane fluoroscopic images of objects such as catheters outside the living body taken from different angles. Thereafter, the method disclosed in Sra et al. uses single-plane fluoroscopic images taken only from one angle to determine the 3D location and orientation of objects within a living body.
The novel method disclosed in the Sra et al. document involves building a map point-by-point as do many other methods directed at map generation. There is therefore an important need to reduce the time and radiation exposure involved in map generation. It is also quite common for cardiac rhythms to change during a medical procedure, and such an occurrence creates the need for the physician to be able to respond in order to learn more about the patient's condition. Maps generated on a point-by-point basis cannot be generated fast enough to be useful in such circumstances.
United States Published Application No. 2016/0235383 discloses a system for compensating for heart movement using coronary sinus catheter images. Focusing on compensating for the motion of an individual catheter, no cardiac parameter maps are generated which are derived from single-plane fluoroscopic images.
With the present invention, in addition to the dramatic decrease in the time required to generate an initial 3D parameter map, it has been found that in some cases, the cardiologist is able to determine all or nearly all of the scope of the medical situation at hand with the initial rapidly-constructed map generated and displayed by the inventive method disclosed herein. If this is not the case, at least such a map may still be highly beneficial by pointing to an important area of concern, indicating to the cardiologist the direction of the next steps to be taken for the patient. In every case, procedure time and total X-ray exposure have been dramatically reduced, both such reductions being highly advantageous to the patient.